1661517204 has 24 divisors (see below), whose sum is σ = 3877954080. Its totient is φ = 553684704.

The previous prime is 1661517197. The next prime is 1661517211. The reversal of 1661517204 is 4027151661.

It is an interprime number because it is at equal distance from previous prime (1661517197) and next prime (1661517211).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30742 + ... + 65330.

It is an arithmetic number, because the mean of its divisors is an integer number (161581420).

Almost surely, 2^1661517204 is an apocalyptic number.

It is an amenable number.

1661517204 is an abundant number, since it is smaller than the sum of its proper divisors (2216436876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661517204 is a wasteful number, since it uses less digits than its factorization.

1661517204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38599 (or 38597 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 1661517204 is about 40761.7124762932. The cubic root of 1661517204 is about 1184.4087691413.

Adding to 1661517204 its reverse (4027151661), we get a palindrome (5688668865).

The spelling of 1661517204 in words is "one billion, six hundred sixty-one million, five hundred seventeen thousand, two hundred four".